Clay-rich exposures near Mawrth vallis, Mars

Perspective view of clay-rich rocks (blue) on the old plateaus around the valley of Mawrth Vallis (left) and the crater Oyama (center), made from a compilation of OMEGA, HRSC and MOLA data. Strangely, no hydrated minerals or sediments were detected either in the channel or where the channel emptied into the basin, but the flood that created the channel seems to have eroded and exposed ancient hydrated clay-rich minerals.